On armor I found this pic relating to various Chinese ERA plates (below). Yes therefore armor can be upgraded. On T 90 that would add to cost if adding new panaromic sight, I am suprised that Indians have not asked for that upgrade with their purchase due to arjun has this sight. Writing to you last on T 90 thread you talked about BMS and that it is essential for any tank, has the T 90 have this option now? To me the competation is or has has been between the Polish, Chinese/Pakistanis and Ukrainians tanks, the other tanks have features that are not currently available for T 90. I expect you will correct me on that last paragraph, I will clarify if need be.
I am hearing that Russia very well may come out with a BMS system along with Relikt armor upgrade package, I have to laugh about that one seeings how alot of folks thought that it could only be accomplished on older T-72 series when in fact it is a better fit with the welded turret design concept, either way we may see a slightly modified T-90 or one that will go through a extensive upgrade in the near future, including all the latest and greatest electronic toys, T-90 can also quite easily recieve these modifications.
The photo that you referenced does show some of the ERA packages that are available, but one must wonder what could actually be lurking inside the main turret protection configuration, cleary this area also can be upgraded if warranted.